“On the Cincinnati Bengals’ second offensive series Friday night, running back Cedric Benson burst into the secondary, running off left guard. Eagles rookie free safety Nate Allen didn’t see Benson until the runner suddenly emerged from a group of players, right in front of Allen, who didn’t have time to launch himself, or otherwise gain leverage. Benson basically ran Allen over, en route to an 11-yard gain.

“I just kind of lost him behind the linemen. No excuses, though . . . I was on my heels. It happens, you just have to bounce back,” Allen said.

On the next play, Allen blitzed, and was in the face of Bengals quarterback Carson Palmer when Palmer unleashed a throw that was picked off by Birds’ corner Dimitri Patterson.

“You gotta have a short memory,” Allen said.

Eagles coach Andy Reid remembered the sequence well; it’s the sort of experience he wants the preseason to provide, as Allen readies himself to start as a second-round rookie.

“He learned a good lesson, right there, and it happens. It happens to the best of them,” Reid said. “He got caught behind the pile, and all of a sudden he didn’t know if the back was going left or right. The back goes right and he kind of stuck his head out there to look, and then it was a train wreck.

“So he knows you have to feel the leverage that your linebackers have and that the blockers have and then you just have to sell out to that position. It was a good lesson learned. I was proud of him because he came right back and made some plays after that that were physical, physical plays. That’s a great lesson to learn. He’s a smart kid. He’ll learn from that and be better for it.”

Allen and the defense put in a pretty solid half against Cincinnati, allowing just seven points to an offense featuring Terrell Owens and Chad Ochocinco. Allen and the first unit saw just six snaps in the preseason opener the week before; he said he was glad to get more work.

“It was a great experience. They’re premier receivers. It was a good test for us, as a defense. I thought we did pretty well containing them. We just had a few mental errors here and there,” Allen said.

For this week at Kansas City, Allen said he feels he can improve on “just little stuff – my alignments, disguising better.””